Trouble with paying that kind of money for a 2080 is that you know in 3-6 month you will get the ti version for the same price. Which is why I would rather get the 2070, see how it fares until the 2080Ti comes out and decide if I can wait until the 3070 comes out
If possible I would love to be able to go from xx70 to xx70 each gen. If it cost about £100-150 to upgrade every 2 years, that is not to bad. It is like being 1 gen behind from the top, but you get a much more efficient card running card. Also you get to have fun trying out the latest gen of cards each time rather than being stuck on a old hot power hungry card which is not great unless watercooled in the summer.
That said certain games like Cyberpunk 2077 will make me want to upgrade to something beefier.